据说是一道挺重要的题，一定背下来嗯……

/**
 * Definition for singly-linked list.
 * struct ListNode {
 *     int val;
 *     ListNode *next;
 *     ListNode(int x) : val(x), next(NULL) {}
 * };
 */
class Solution {
public:
    ListNode* reverseList(ListNode* head) {
        ListNode* p = head;
        ListNode* prev = NULL;
        ListNode* temp;
        while(p){
            temp = p->next;
            p->next = prev;
            prev = p;
            p = temp;
        }
        return prev;
    }
};

python的实现和cpp没什么区别， 就不贴了